1. Field of the Invention
This invention relates to an image sensing device, a program for installing an image sensing program and a related system.
2. Description of the Related Art
FIG. 8 is a block diagram illustrating the construction of an electronic camera according to the prior art.
As shown in FIG. 8, the optical image of a subject that has entered via a lens 1 and diaphragm/shutter 2 is converted to an electrical image signal by an image sensing element 3 such as a CCD. This image signal is subjected to pre-processing such as CDS (correlated double sampling) and AGC (automatic gain control) by a pre-processing circuit 4, the processed signal is converted to a digital signal by an A/D converter 5 and the digital image signal is then processed by a process circuit 6 to obtain image data having a prescribed format. These image data are temporarily stored in a memory 7, after which they are subjected to compressing coding by a compression circuit 8 and recorded on a recording medium 9. A memory controller 10 controls the A/D converter 5 and compression circuit 8, and a CPU 11 serves as system controller to control the overall system.
In the electronic camera described above, the program executed by the CPU 11 serving as the system controller is permanently provided in a ROM in the form of firmware, and the manner in which an image is to be recorded is decided beforehand when the apparatus is produced at the factory. This means that the diverse needs of users cannot be satisfied. Accordingly, the applicant has previous proposed a technique through which external programs are supplied to a camera from an external host computer, the programs are recorded on the recording medium 9, the camera is provided with a mechanism that is capable of executing an external program at the time of photography and image information recorded by the external program is capable of being expanded.
It has been contemplated to use a bar code, for example, as the external program, read the bar code immediately after photography and record the read information on the recording medium 9 as information attached to the photographed image. It has also been contemplated to record the photographed image after subjecting it to certain processing. For example, it is possible to supply an external program which converts the photographed image to a line-art image, an edge detection image, etc. Since these converted images generally contain much less data than the original image obtained by photography, data compression efficiency can be facilitated and a large number of images can be recorded by the recording medium 9.
The proposed techniques described above extend photography by applying some processing to the original image obtained by photography. However, since this function is not necessarily desired by all users, it is provided as an external program.
In a case where a camera is provided with external programs in the prior art described above, the camera itself and the external device for providing the camera with the external programs are not capable of ascertaining whether the external programs can be run by the version of the camera or by a control program with which the ROM is furnished in advance. In some cases there is the danger of operation hang-up, meaning that the camera cannot be used normally unless it is reset. Malfunctions can occur as well.
Further, when a camera is provided with external programs in the aforesaid prior art, the external programs are transferred from the external device, such as a computer, to a non-volatile memory within the camera or to a recording medium that is capable of being extracted. One external program is selected by operating the camera, thereby selecting the photographic mode. Alternatively, the photographic mode is selected by selecting an external program, which is capable of producing a desired image, by referring to an image file created by photography in the past.
These photographic modes are significant in that they serve as instruments for extending the functionality of the camera. It can be predicted that after the camera is made available for sale, external programs capable of implementing several effective photographic modes will be provided by the camera maker or by other vendors.
In such case, it is possible that an external program for one photographic mode will be installed and used in a number of cameras possessed by a number of users. If, when an external program on an extractable recording medium is recorded, the recording medium is used in cameras or in computers, it is possible that the external program will be transplanted to many recording media or memories. In a case where an external program for obtaining a desired image is established in another camera by referring to an image file created by photography in the past, it is conceivable that the external program used in the earlier photography will be transplanted to the other camera. This is a problem because it may lead to infringement on the copyright of the external program.
In view of these problems, therefore, an object of the present invention is to prevent an external program from being installed in a camera for which the program is not suited.
Another object of the invention is to prevent use of an external program not suited to a camera.
A further object of the invention is to prevent the unlawful installation of an external program.
Yet another object of the invention is to inhibit use of an external program that has been installed unlawfully.